This invention generally relates to photography and the need in that industry for a level or horizontal photographic surface with zero curvature. More particularly, this invention relates to microfilming where the stated need is critical. Specifically, this invention provides an automatic system for leveling books, volumes or otherwise unmanageable documents, for holding such objects being photographed at a level plane and at near zero curvature.
Current practice is generally limited to the use of props, boards, wedges or clips to accomplish the leveling or curvature problems. This archaic method does not contribute to quality or production and lacks precision in providing a level surface free of curvature. Furthermore, production is impeded by continual shifting and changing of the props, wedges and clips by the operator.
The device of this invention presents the industry with a system that uses air as the leveling agent and a transparent cover for the material being photographed, to enhance the leveling effect and reduce the curvature of volumes or difficult documents, to near zero curvature. Moreover, this system facilitates the rotation of the spine of volumes being filmed. The bulk of the volume weight being supported by the air containers, the spine of the volume has less friction on the supporting table and more freely rotates as the weight shifts. This system introduces a novel coupling of the transparent cover to a base which permits adjustment of the transparent cover by elevating or lowering it, at its level plane, to meet the needs presented by thick or thin volumes or other documents and a means to raise and lower said cover to turn or adjust pages being filmed.
Genesis for the invention grew out of the obvious and highly visible need evidenced in widespread microfilming operations. The subject of this petition is a refinement of several attempts to accomplish the objective. The original concept involved hydraulics, worm drive gears and small reversible direct current motors. These approaches were abondoned for various reasons, such as danger of damage to the documents being filmed, or as being impractical.
The system now presented is novel, simple in its operation, cost effective and easy to manufacture. Having been reduced to practice, it has been tested intensively and found to be functional as well as practical.
While the industry has long been in need of a device for leveling material being photocopied or microfilmed, the invention here presented was slow to reach fruition.
Diligent search of existing art does not disclose pneumatics being used for the specific purpose proposed herein. While the indentical inventive concept was not found, U.S. Pat. Nos. 4,035,077; 3,995,955; 3,679,302; 3,630,612; 3,352,222; 2,591,449; 1,780,701; 1,612,832; 978,719; 759,469 and 679,740 were critically examined. The concepts therein utilize springs, mechanical pressure, leverage and air cushions in the print making process as distinguished from the photographic or microfilming operations. Only one, Patent No. 3,679,302, refers to but makes no specific claim for the use of a pneumatic system. Moreover, that application does not detail its operation and represents a simple and incomplete function of such a system.